Ultrasonic Bat Detector Circuit

The sound from the detector is heard at the same time the call is emitted by the bat.

Ultrasonic bat detector circuit.

A device that lets you listen to and record the sounds emitted by bats. Heterodyning and frequency division are real time methods i e. The figure above shows a simple ic 741 based ultrasonic sound sensor alarm circuit. Heterodyning is the most sensitive method of the two but only transforms a small portion of the ultrasonic frequency range.

Firstly such transducers are very responsive to ultrasound and thus produce large output voltages upon detection as compared to a generic audio microphone. Results can be displayed in real time with 30 second delay in either text or spectogram or bar chart format. It has been suggested that bats utilize delay times arrival time differences and the doppler effect to interpret echoes. The mic input is fed to the inverting input of the ic pin 2.

Full spectrum ultrasonic audio recording in mono at 384 ks per second. These sounds lie in a frequency range above the human audible range and thus can t be heard directly. Detection of the high frequency clicks bats emit must be done with an ultrasonic transducer for two reasons. The detecting device used here is an ordinary electret condenser mic.

Runs off a 12 v battery or any power supply from 6 to 16 v. By down converting the ultrasound into our audible range we can indirectly detect it and at least enjoy a window into the hidden world of echolocation. As you probably know bats emit ultrasonic sounds for the purpose of echolocation.